The outcome of this argument (and, very likely, of the election itself) will depend on how the public defines “middle class.” The left insists that you qualify for that status based on the money you earn: if you bring home too little—or too much—you’ve entered some other segment of the population.

But if Republicans can make the case that membership in the middle class is based more on worldview and values rather than pay stubs, they can claim the coveted title “middle-class defenders” and even make the case that it’s Obama, not Romney, who’s most out of touch with the American mainstream.

Polling data suggest that most Americans are already inclined to view the middle-class designation as something more than a matter of income: overwhelming majorities describe themselves that way even when their earnings put them far below or far above the normally assigned boundaries. A fascinating, in-depth study from the Pew Research Center (2008) showed that 41 percent of Americans with family incomes below $20,000 said they are middle class—even while the federal government classifies them as below the poverty line. At the other end of the spectrum, 33 percent of families with incomes above $150,000 also considered themselves middle class. A recent Washington Post-ABC News poll (April 2012) showed a full 59 percent who said they saw themselves as “middle class” or “upper middle class.” A scant 3 percent said they were “better off than that.”

With significant proportions of those who live in poverty—as well as those who draw six-figure incomes—claiming the same middle-class designation, it ought to be obvious that they share common values that count as more important than economic circumstances. Many families struggling at the edge of survival (including, no doubt, many immigrant families) feel proud of practicing middle-class virtues, and feel confident those virtues will bring their ultimate financial reality more in line with their cultural aspirations. Many other Americans (like the famous “Millionaires Next Door” celebrated in a series of bestselling books) may have earned enough to leave bourgeois life behind but still they still choose to toil away at the daily grind, spending sparingly, attending church, saving for the future and otherwise honoring their middle class roots.

Those roots feature a range of behaviors and characteristics—frugality, hard work, faith, marriage, personal accountability, respect for authority—more commonly associated with the conservative side of the political spectrum. In fact, those values have historically drawn contempt both from academic and media elites as well as the urban poor, who mock that segment for its timidity, materialism, and conformity. The suburbs—natural habitat for the middle-class species—regularly draw contempt in pop culture, derided by urban activists as greedy, bland, and soulless while New Class sophisticates shun a universe of SUVs, soccer leagues, and second mortgages. No one can mistake the way that Manhattan, exclusive enclave of the very rich and the very poor, looks down on the middle-class neighborhoods of Queens or Staten Island.

When Democrats promise to defend the middle class, they don’t seem eager to defend middle-class values. Instead, they emphasize programs designed to keep middle-class numbers high by making sure that fewer people get rich—or stay poor. A family earning $250,000 a year and with, say, five children may well consider itself middle class, but in President Obama’s oft-expressed view, that family counts among “the millionaires and billionaires” who need to pay more to the government. The left’s effort to promote middle-class numbers involves twin priorities: to give enough money to poor people so they can join the bourgeoisie and to take enough money from prospering people so they’ll feel less able to wander away from the middle-class reservation.

Among the 50 percent of the electorate who reported family income between $50,000 and $150,000, McCain actually won in 2008—with a narrow majority.

To conservatives, this redistributionist agenda constitutes an affront to the self-reliant approach that enabled prior generations to rise to the middle class in the first place. Taking wealth from people who earned it and giving it to people who didn’t may, arguably, advance the economic interests of Middle Americans, but it also profoundly violates their traditional sensibilities.

And nothing offends those sensibilities more profoundly than profligate spending and runaway debt. In a memorable column about food-stamp fraud, Warren Kozak writes: “My grandmother did not serve on the President’s Council of Economic Advisers. She did not have an MBA from Harvard. She never went to high school because she had to go to work to support her family. But she gave me an astute piece of financial advice when I was about to enter the world. ‘Never,’ she told me, ‘spend more than you earn’ and ‘always try and save a little something.’”

Nearly every middle-class American has heard similar advice from a grandparent, parent, uncle, or godfather, and on this basis Mitt Romney might actually claim the advantage over his presidential rival when it comes to staying in touch with middle-class values. Despite their vast wealth, the Romneys famously live below their means, flying coach class when they use commercial airlines, with Mitt idiosyncratically ironing his own shirts in hotel rooms rather than sending them out to be pressed. During his early childhood, the candidate’s father (who never earned a college degree) struggled to make his way in business, while Obama’s parents were both globe-trotting, left-leaning academics who ignored financial considerations while pursuing their research and advanced degrees.

For Romney, even the infamous dog-on-the-roof vacation was a long road trip in the family station wagon—the sort of car that a chic, sophisticated, big-city couple like the Obamas would scrupulously avoid. Even as a recent law-school graduate, young Barack managed to take Michelle on an exotic and expensive extended vacation in Bali. By his own account, he chose to launch his ambitious and costly state-senate campaigns before he’d made much dent in paying off tens of thousands of student loans—the sort of bold, arguably irresponsible move that defies the essence of bourgeois caution.

In fact, nearly everything about the president’s biography and his astonishing rise shows him consistently free of the restraints of convention most commonly associated with Middle America—and endears him to his admirers as the hippest president ever to occupy the Oval Office, or at least the coolest customer since JFK. Romney, by contrast, comes across as hopelessly, incurably square and he would count as the least trendy, most Ozzie-and-Harriet president since Ike.

But this dorky nature may enable Romney, of all people, to stand up as the defender of the middle class, far more representative of its suburban values than his cosmopolitan opponent. The Great American Middle has never been hip, or cool, or stylish, drawing ill-disguised contempt from brooding intellectuals, aspiring autobiographers, and part-time professors like the present president. Romney, by contrast, offers a hale-and-hearty, Midwestern Rotarian aura that much of Middle America may find far more down to earth.

In 2008, Barack Obama ran most strongly among voters earning less than $30,000, and those who brought home more than $200,000. Among the 50 percent of the electorate who reported family income between $50,000 and $150,000, McCain actually won—with a narrow majority.

Romney can improve on that showing and win the election by tagging Obama as the candidate of the top and the bottom, claiming the Great American Middle as his own. He could do so by emphasizing his ongoing identification with the middle class and its core values, while showing his disapproval of the trendy avatars of the hyper-educated New Class.

Republicans can appeal to wavering suburban voters most effectively if they clinch the case that the real war on the middle class is cultural, and not just economic. Stylistic contrasts between the candidates could well benefit Mr. Square as much as Mr. Cool, while conservatives make the argument that middle-class survival is, ultimately, a matter of soul more than social programs.